title: cDNA isolation of Alzheimer's amyloid precursor protein from cholinergic nerve terminals of the electric organ of the electric ray.
abstract: Alzheimer's amyloid precursor protein (APP) is a transmembrane protein containing three phosphorylation sites in its cytoplasmic domain. In the present study, we isolated cDNA of APP from electric ray electric lobe (elAPP). This APP (elAPP699) consists of 699 amino acids, contains the beta-amyloid domain and has 80.7% similarity with the human APP695 isoform. The cytoplasmic domain, including three phosphorylation sites, was completely conserved. In the nerve terminals of the cholinergic neuron from the electric ray electric organ, we found elAPP699 existed exclusively in the mature form. We found the phosphorylated form of mature elAPP699 in the nerve terminal as well as in cell body. Immature elAPP699 was not subject to phosphorylation. Our findings indicate that, in neurons, the phosphorylation of APP occurs after maturation.
authors.affiliation: Laboratory of Neurobiophysics, School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Iijima
authors.forename: D S
authors.initials: DS
authors.lastname: Lee
authors.forename: J
authors.initials: J
authors.lastname: Okutsu
authors.forename: S
authors.initials: S
authors.lastname: Tomita
authors.forename: N
authors.initials: N
authors.lastname: Hirashima
authors.forename: Y
authors.initials: Y
authors.lastname: Kirino
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000595:Amino Acid Sequence; D016564:Amyloid beta-Protein Precursor / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002451:Cell Compartmentation; D002799:Cholinergic Fibers / Q000737:chemistry; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000302:isolation & purification; D004557:Electric Organ / Q000737:chemistry*; D006031:Glycosylation; D006801:Humans; D008969:Molecular Sequence Data; D010766:Phosphorylation; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014101:Torpedo / Q000235:genetics*
chemical_list: D016564:Amyloid beta-Protein Precursor; D018076:DNA, Complementary